49 47 45 5 3 1 +---------//-----+ | H H H //H H H | | ======//====== | | H H H// H H H | +-----//---------+ 50 48 46 6 4 2
 (at the Computer)
 (at the Computer)
50 PIN ?? at the Computer.
| Pin | Name | Dir | Description | 
|---|---|---|---|
| 1 | /CS1 |  | Memory Read in addresses 4000-7FFF | 
| 2 | /CS2 |  | Memory Read in addresses 8000-BFFF | 
| 3 | /CS12 |  | Memory Read in addresses 4000-BFFF | 
| 4 | /SLTSL |  | Low when Slot 2 (cartridge slot) is selected | 
| 5 | n/c | - | Not connected. | 
| 6 | /RFSH |  | Refresh signal from CPU | 
| 7 | /WAIT |  | OC, Tells CPU to wait. Refresh signal is not maintained | 
| 8 | /INT |  | OC, Requests a interrupt to CPU (call to addr 38h) | 
| 9 | /M1 |  | CPU fetches first part of instruction from memory. | 
| 10 | /BUSDIR |  | NC, was used to control the data direction. | 
| 11 | /IORQ |  | I/O request signal. (Address=Port) | 
| 12 | /MREQ |  | Memory request signal. (Address=Address) | 
| 13 | /WR |  | Write signal (strobe) | 
| 14 | /RD |  | Read signal (strobe) | 
| 15 | /RESET |  | Reset | 
| 16 | n/c | - | Not connected. | 
| 17 | A0 |  | Address 0 | 
| 18 | A1 |  | Address 1 | 
| 19 | A2 |  | Address 2 | 
| 20 | A3 |  | Address 3 | 
| 21 | A4 |  | Address 4 | 
| 22 | A5 |  | Address 5 | 
| 23 | A6 |  | Address 6 | 
| 24 | A7 |  | Address 7 | 
| 25 | A8 |  | Address 8 | 
| 26 | A9 |  | Address 9 | 
| 27 | A10 |  | Address 10 | 
| 28 | A11 |  | Address 11 | 
| 29 | A12 |  | Address 12 | 
| 30 | A13 |  | Address 13 | 
| 31 | A14 |  | Address 14 | 
| 32 | A15 |  | Address 15 | 
| 33 | D0 |  | Data 0 | 
| 34 | D1 |  | Data 1 | 
| 35 | D2 |  | Data 2 | 
| 36 | D3 |  | Data 3 | 
| 37 | D4 |  | Data 4 | 
| 38 | D5 |  | Data 5 | 
| 39 | D6 |  | Data 6 | 
| 40 | D7 |  | Data 7 | 
| 41 | GND |  | Ground | 
| 42 | CLOCK |  | CPU clock, 3.579 MHz | 
| 43 | GND |  | Ground | 
| 44 | SW1 | - | NC, Insert/remove detection for protection | 
| 45 | +5V |  | +5 VDC (300mA max /slot) | 
| 46 | SW2 | - | NC, Insert/remove detection for protection | 
| 47 | +5V |  | +5 VDC (300mA max /slot) | 
| 48 | +12V |  | +12 VDC (50mA max /slot) | 
| 49 | SOUNDIN |  | Sound input (-5dBm) | 
| 50 | -12V |  | -12 VDC (50mA max /slot) | 
Note: Direction is Computer relative Peripheral.
| Contributor: | Joakim Ögren | 
| Source: | Mayer's SV738 X'press I/O map | 
  Copyright © The Hardware Book Team 1996-2004.
  May be copied and redistributed, partially or in whole, as appropriate.
  Document last modified: 2002-01-10